RHEL 7 little but valuable improvement.

In RHEL 6, service management was sometimes slightly painful.
Each time you wanted to start or enable a service, you had to perfectly remember its name.
For example, when you wanted to set up a ntp client, you had to install the NTP package: # yum install ntp
Then, you had to enable the service: # chkconfig ntpd on
Finally, you had to start the service: # service ntpd start
As the package name was different from the service name, you had to remember both names and sometimes use commands like: # chkconfig | grep ntp

With RHEL 7, Systemd involves new commands but you get exactly the same steps (by the way, package name and service name are still different in this case):
You have to install the NTP package: # yum install ntp
Then, you have to enable the service: # systemctl enable ntpd
Finally, you have to start the service: # systemctl start ntpd
The improvement appears when using the systemctl command: you get bash completion!
According to Ben Breard, you get this feature by default except in the minimal installation configuration.

When not sure about the service name, type the beginning of its name and press the tab key!
Start by getting the service status: # systemctl status ntpd
Then start/stop/enable/disable it according to your needs.